More precisely, the invention concerns a lighting system for mounting an electrical lamp onto a power supply, comprising:                an electrical lamp having an electrical lamp connector,        a holder having a front electrical connector adapted to be back-connected to a power supply,                    a cap to interface the electrical lamp and the holder, extending along a mounting direction between a top side for receiving the lamp connector and an opposite bottom side for receiving the holder connector, and having axial holes extending between the bottom side and the top side for receiving within at least a part of an electrical cap connector able to electrically connect the lamp connector with the holder connector once the lighting system is assembled;wherein the cap and holder have attached means adapted to cooperate with one another in the mounting direction so as to mount and electrically connect the cap with the holder.                        
A lighting system of this type is disclosed for instance in WO-A-2004/015331.
Although the lighting system which is described in this document is satisfactory, a general need with lighting systems of this type is to avoid that an electrical connection of the cap to the holder may fail and result in jamming of the cap on the holder.